Electrolytic cell



Feb. 5, 1935. Q RE|NHARDT 1,990,463

ELECTROLYTIC CELL,

Fild Feb. 2, 1952 F93 4 0Z6 FIGLZ.

f 61 LL)" v 20 14 1 62 10 I 20 IIIEI 14 INVENTOR OTTO If. REIIVHARDT BY HIS ATTORNEYS tive electrode of the cell.

Patented Feb. 5, 1935 TATES ELECTROLYTIC CELL Application February 2,

Claims.

This invention relates to electrolytic cells and more particularly to cells for primary batteries,

especially although not necessarily dry cells.

In the process of manufacture of dry cells, the battery mix is combined with and around a rodlike carbon electrode serving, when the cell is completed, as a positive electrode. This unit is then inserted in a zinc cup serving as the nega- A fiber washer, usually, is inserted in the cup over the carbon electrode and a brass cap is afiixed thereto. The cell is then sealed by a layer of insulating compound, such as asphaltum or other sealing material poured on top of the washer and allowed to harden. Such application of sealing material is expensive and awkward and in use of the cells,

it is found that the sealing material often shrinks or cracks permitting the escape of the gases formed by the electrolytic action in the cell and also of the electrolyte, thus permitting the cell to deteriorate.

It has heretofore been proposed to cover such cells with a metal top which, of course, was in electrical Contact with the shell serving as one terminal of. the cell. This necessitates the exposure of the brass cap on the carbon electrode for use as the other terminal of the cell and difliculty has been experienced in the practical manufacture of such cells in effectively sealing and insulating the metal top from the brass cap electrode.

One object of the present invention is the provision of an electrolytic cell having a metal top which shall be hermetically sealed.

The invention also seeks a cell construction which is practical from the standpoint of ease and cheapness of manufacture and durability in use. In accordance with the invention, an electrolytic cell, having an electrode therewithin surmounted preferably by a conductive cap, comprises a cup shaped shell having at least one conductive portion serving as one terminal. tallic closure for the open end of the shell is formed with an aperture in register with the cap and dielectric means is disposed upon opposite sides of the top and is formed with an aperture in register with but of less diameter than the aperture in the top. Preferably conductive means passes through the apertures and permanently clamps the dielectric means and top together and this conductive means is in electrical connection with the cap on the electrode. More specifically, a metal top is secured either by crimping or soldering to the zinc shell, the metal top having an aperture centrally thereof. Above A me-- 1932, Serial No. 590,407

and below the metal top are disposed fiberwashers having apertures in register with but of smaller diameter than the aperture in the metal top. These three apertured members are conveniently secured together by metallic clamping means, such as an eyelet or rivet, which may be integral with or separate from the brass cap surmounting the carbon electrode, suitable means, such as solder, being provided, if required, for securing the parts together.

It is also an object of the invention to provide a metallic closure for the end of a flashlight cell which can be readily assembled, as by automatic machinery. To this end, the several component parts of the closure are so formed as to facilitate the centering of one part with respect to another and the edges of the respective parts are curved to permit the insertion of one part within another.

These and other objects of the invention and the means for their attainment will be more apparent from the following detailed description, taken in connection with the accompanying drawing illustrating various modifications by which the invention may be realized, and in which:

Figure 1 is a view in side elevation showing an electrolytic cell to which the invention is ap-' plied, the intermediate portion being removed to save space and parts being broken away to show the top and sealing means in section;

Figure 2 shows a modified form of sealing means in which an eyelet clamping the fiber washers'to the top is secured to the brass cap on the electrode by solder;

Figure 3 shows still another modification in which the brass cap is an element of the washer clamping means; Y

Figure 4 shows one means of securing the top to the shell by crimping;v

Figure 5 shows a metal top having a peripheral flange secured to the shell by soldering;

Figure 6 is a View showing the upper end of a cell in which the metal top construction facilitates assembly in mass production; and

Figure '7. is a plan view of the construction shown in Figure 6, parts being broken away in the interest of clearness.

Referring first to Figure l, a cup shaped zinc shell 10 having a closed bottom 12, preferably integral therewith, is adapted to contain the elements of the electrolytic cell. Surrounding the zinc cup, is an insulatory casing 14 open at the bottom whereby the bottom 12 is exposed to serve as one terminal of the battery. Usually the shell contains a liner 16 and within the liner is the bobbin 18, consisting of the carbon mix, surrounding the carbon electrode 20, the mix being wrapped with a bibulous wrapper or envelope secured in some convenient fashion, as by the cord 22, in place. Telescoped over the end of the carbon rod 20 and conveniently resting upon the bobbin, is a washer 24 of fiber or other nonmetallic material.

The upper end of the shell is sealed by a metal top 26. In this instance, the metal top takes the form of a disc of metal disposed just inwardly of and fitting within the end of the cylindrical wall of the shell 10 to which the disc is secured as by the solder 28. If desired, the top may be ofiset centrally in an upward direction, as at 27, so as to be spaced from the cap 40 on the carbon electrode. It is apertured, as at 30. Below the top is disposed a washer 32 which, for purposes of assembly, is of a diameter suflicient to be conveniently received and fixed within the offset part 27 of the top. This washer is of non-conductive material, such as fibre, and is apertured as at 34, the aperture being of a diameter less than the diameter of the aperture 30 in the cap. A similar, but preferably somewhat smaller washer 36 is disposed above the top, this washer being also formed with an aperture in register with the apertures in the top and washer 32, the diameter being less than the aperture in the top 26 but desirably substantially equal to the aperture in the washer 32.

In the modification illustrated in Figure 1, in place of the usual brass cap, a cylindrical member 40 of conductive material, such as brass, is formed with an inwardly directed flange 41 at one end to define an aperture in its bottom of substantially the same diameter as the apertures in the washers 32 and 36, and this perforated cap 40, 41 is of a diameter to fit snugly over the carbon rod 20, when inverted, in a manner well understood. Prior, however, to its application to the carbon rod, it is permanently assembled with the top by means of a rivet or eyelet-like member 44, which is passed through the hole 42 and has its outer end 46 crimped over to draw the cap against the assembled discs thereby holding the entire structure together. Thus when the cap 26 is applied to the shell and soldered in position, the

brass cap is held in electrical connection with the carbon rod. The washers 32 and 36, being clamped to the top and snugly fitting the rivet means 44, effectively seal the opening 30 against the passage of fluid.

The hole 30 in the top- 26, being of greater diameter than the eyelet means, is out of electrical connection therewith and thus the eyelet 46, which is in electrical connection with the carbon terminal of the battery but which is insulated by the washers 32, 36 from the metal top 26 in electrical connection with the zinc terminal of the battery, still serves, by means of the turned over end 46, as the central terminal of the battery. The space within the eyelet 44 may, if desired, be

: filled or closed with solder, as in the modification top 26 by means of an eyelet 50 while a brass cap 52 is initially placed on the carbon rod 20. When the top is secured to the walls of the shell 10 in any convenient fashion, as by the solder 28, the eyelet 50 is held in engagement with the cap 52. To further seal the joint between the parts 50 and 52, and make good electrical connection therewith, solder 54 may be dropped within the eyelet.

In Figure 3, a cylinder 60, somewhat similar to that illustrated in Figure 1, has the walls drawn inwardly into a somewhat tubular shape of smaller diameter, as at 62, to form a shoulder 64 resting on the top of the rod 20. When the parts are assembled, this tubular portion 62 is passed through the registering holes in the washers 32 and 36 and top 26 and the upper end of the tube 62 is crimped over, as at 66, so that the washers and top are clamped between the crimped-over portion and the shoulder 64. This again makes an effective seal and when the top is secured in position, the terminal means is held in good electrical connection with the carbon electrode.

The top, no matter how secured, sealed and insulated with respect to the central terminal of the cell, may be secured to the wall of the shell in any convenient fashion. As shown in Figure 4, the diameter of the top '70, initially, is materially greater than the diameter of the shell 72 and the perimeter of the top is crimped over the rim of the shell, as at 73, so as to form a tight joint at that point. As shown in Figure 5, the perimeter of the top 74 may be bent upwardly as a flange 76 to nest within the shell 10 and be secured thereto in any convenient fashion such as by welding or soldering.

Figures 6, and 7 illustrate a construction in .which the several component parts are readily assembled in exact position to be secured together, say, with automatic machinery. Centrally the metal top 78 is pressed upwardly (as viewed in Figure 6) to form an inverted circular depression 79- and for a distance suflicient to receive an insulatory washer 80 above the cap 82 on the central carbon electrode 20 of the dry cell. Centrally, the top is apertured, as at 84. The washer 80 is of a size to be fairly snugly received in the depression 79 and be centered thereby so that the hole 85 therein is concentric with the hole 84 in the top, although, of course, of lesser diameter. The edge or corner 86 forming the rim of the depression is curved on a relatively large radius, as shown, so that in assembling the washer within the depression, it will 'with.

As in the modification of Figure 1, the cap 82, with its central perforation 83, is first assembled with the insulatory top washer 36 by means of an eyelet 44, which is spaced from the top 78 by the washers so as to be out of electrical connection therewith. The assembled top is then set within the rim of the zinc cup 10 with the cap 82 fitted over the electrode 20.

In commercial operation, the electrode 20 is often eccentric of the cup 10 and to facilitate the telescoping of the cap 82 over the electrode,

the mouth of'the cap 82 is flared outwardly, as at 87, with the inner surface curved on a gradual curve so that the mouth of the cap 82 will telescope over the electrode 20, even though ofl? center, and in moving within the cup 10 tend to shift and center the electrode 20. 3

At its periphery, the top 78 is formed with an upwardly extending peripheral flange 90 by which the top 78 and cup 10 are readily and conveniently joined and secured together. To facilitate the entrance of the top 78 within the cup 10 and its centering therewithin, upon assembly, the outer corner, formed where the flange 90 is joined to the top 78, is rounded on a curve of relatively large radius, as at 92. Thus, even though the top is slightly off center when first applied to the cup, it readily slips into place and this curvature 92 cooperates with the flaring mouth 8'7 in the assembly of the parts to facilitate the centering of the electrode 20.

It will thus be seen that an extremely simple construction has been provided involving a metal top in which the central terminal of the cell passes through the metal top but is insulated therefrom and the joint therebetween is hermetically sealed in a practical, permanent and convenient fashion. The construction is readily adapted to assembly in mass production.

Various modifications will occur to those skilled in the art in the devices used to clamp the sealing washers to the top as well as in the means for connecting the clamping means to the conductive cap on the carbon electrode, as well, also, in the configuration of the component ele ments, and no limitation is intended by the phraseology of the foregoing description or illustrations in the accompanying drawing, except as indicated in the appended claims.

What is claimed is:-

1. An electrolytic cell having a central electrode therewithin surmounted by a conductive cap and a cup shaped shell having at least one conductive portion serving as one cell terminal, a metallic closure for the open end of the shell formed with an aperture in register with the cap, a washer of insulating material disposed beneath the closure having an aperture of less diameter than the aperture in the closure, a second washer of insulating material disposed above the closure and having an aperture of less diameter than the aperture in the closure, an eyelet passing through v the apertures and clamping the closure between the washers and in engagement with the conductive cap and means securing the eyelet to the conductive cap in electrical connection therewith, the exposed portion of the eyelet serving as the other terminal of the cell.

2. An electrolytic cell having a central electrode therewithin surmounted by a conductive cap and a cup shaped shell having at least one conductive portion serving as one cell terminal, a metallic closure for the open end of the shell formed with an aperture in register with the cap,

a washer of insulating material disposed beneath the closure having an aperture of less diameter than the aperture in the closure, a second washer of insulating material disposed above the closure and having an aperture of less diameter than the aperture in the closure, an eyelet passing through the apertures and clamping the closure between the washers and in engagement with the conductive cap and solder securing the eyelet to the conductive cap.

3. An electrolytic cell having a central electrode therewithin surmounted by an apertured conductive cap and a cup shaped shell having at least one conductive portion serving as one cell terminal, a metallic closure for the open end of the shell formed with an aperture in register with an aperture in the cap but of greater diameter, a washer of insulating material disposed beneath the closure having an aperture of less diameter than the aperture in the closure, a second washer of insulating material disposed above the closure and having an aperture of less diameter than the aperture in the closure, an eyelet passing through the apertures in the cap, washers and closure and clamping the closure between the washers and securing the cap thereto, the exposed end of said eyelet serving as the other cell terminal.

4. An electrolytic cell having a central electrode therewithin and a cup shaped shell having at least one conductive portion serving as one cell terminal, a metallic closure for the open end of the shell formed with an aperture in register with the electrode, a washer of insulating material disposed beneath the closure having an aperture of less diameter than the aperture in the closure, a second washer of insulating material disposed above the closure and having an aperture of less diameter than the aperture in the closure, a hollow cylindrical member of conductive material passing through the apertures and having an inner end portion of increased diameter telescoped over the end of the electrode, the outer end being turned outwardly and clamping the closure between the washers against the inner end of increased diameter.

5. An electrolytic cell having a central electrode therewithin surmounted by a conductive cap and a cup shaped shell having at least one conductive portion serving as one cell terminal, a metallic closure for the open end of the shell formed with an aperture in register with the cap. a washer of insulating material disposed beneath the closure having an aperture, a second washer of insulating material disposed above the closure and having an aperture, an eyelet passing through the apertures and clamping the closure between the washers and in engagement with the conductive cap and means securing the eyelet to the conductive cap in electrical connection therewith, the exposed portion of the eyelet serving as the other terminal of the cell.

O'I'IO KARL REINHARDT. 

